+void erb_set_done_callback(struct erb_rend *erb, erb_done_func donecb, void *cls);
+
+void erb_queue_frame(struct erb_rend *erb, unsigned int job_id);
+void erb_queue_block(struct erb_rend *erb, unsigned int job_id, int x, int y,
+ int width, int height);
+void erb_wait(struct erb_rend *erb);
+
+void erb_primary_ray(struct erb_rend *erb, struct erb_ray *ray, int sample);
+void erb_sample_ray(struct erb_rend *erb, struct erb_ray *ray, float *col);
+